Natural Selections
Common stork's bill or redstem filaree, Erodium circutarium, is flowering now on the plains and in the foothills. Its blooms are small, just 10 to 15 mm across, but such a striking shade of deep lavender that they catch the eye
The song spread is critically important in defense of a territory and the song is also evaluated by females as a facet of courtingFrom the branch above me, a male red-winged blackbird took a deep breath, hunched up his shoulders, flared the feathers
Introductions, both accidental and purposeful, frequently have tragic consequencesAmerican elms, Ulmus americana, are native to North America from Saskatchewan to Nova Scotia and from Texas to Florida. They grow 60 to 80 feet tall, with a thick
The flowers of salt and pepper are tiny and arranged into compound groups called umbels, or bouquets in the shape of an umbrella
Two simple contrasts illustrate how the environments occupied by tiger whiptails differ in fundamental waysA long slender lizard moved among trees in a pinyon-juniper woodland on the Colorado Plateau, searching the accumulated debris beneath the
Understanding genetic diversity in a species is especially important for conservation and restoration efforts
The world is full of robber flies—approximately 7,000 species have been recognized worldwide and 1,000 are native to North America
The persistence of two colors everywhere suggests a balance of evolutionary forces
From the caliche soils of southeastern Colorado to crevices in bare sandstone on the Colorado Plateau, stemless four-nerved daisies show remarkable variation in growth form